Draw articulated parts in the purchase menu.

[Xotic750]

To preserve backwards compatibility, OpenTTD should only do so if the NewGRF sets some flag. Such a flag could be per-vehicle (e.g. a bit in the misc_flags property, 0x27 for trains) or per-grf (e.g. by setting a bit in parameter 0x9E).

I would like to see this feature because I would like articulated tenders for steam trains to be displayed in the purchase menu without the need of creating extra sprites for this purpose alone.

Thanks for the consideration.